Add test

python/tests/test_rdata.py

@@ -2,7 +2,8 @@
 import amici
 import numpy as np
 import pytest
-from numpy.testing import assert_array_equal
+from amici.numpy import evaluate
+from numpy.testing import assert_almost_equal, assert_array_equal
 
 
 @pytest.fixture(scope="session")
@@ -39,3 +40,27 @@ def test_rdata_by_id(rdata_by_id_fixture):
     assert_array_equal(
         rdata.by_id(model.getStateIds()[1], "sx", model), rdata.sx[:, :, 1]
     )
+
+
+def test_evaluate(rdata_by_id_fixture):
+    # get IDs of model components
+    model, rdata = rdata_by_id_fixture
+    expr0_id = model.getExpressionIds()[0]
+    state1_id = model.getStateIds()[1]
+    observable0_id = model.getObservableIds()[0]
+
+    # ensure `evaluate` works for atoms
+    expr0 = rdata.by_id(expr0_id)
+    assert_array_equal(expr0, evaluate(expr0_id, rdata=rdata))
+
+    state1 = rdata.by_id(state1_id)
+    assert_array_equal(state1, evaluate(state1_id, rdata=rdata))
+
+    observable0 = rdata.by_id(observable0_id)
+    assert_array_equal(observable0, evaluate(observable0_id, rdata=rdata))
+
+    # ensure `evaluate` works for expressions
+    assert_almost_equal(
+        expr0 + state1 * observable0,
+        evaluate(f"{expr0_id} + {state1_id} * {observable0_id}", rdata=rdata),
+    )